Water-tube boiler



Jan; 6, 1931. H, J. KERR WATER TUBE BOILER Original Filed Dec. 7 6 Sheeta-Shet 1 I INVENTOR. W 9.14 BY ATTORNEYS.

Jan. 6, 1931. H .1. KERR WATER TUBE BOILER Original Filed Dec. 28, 1923 6 Sheets-Sheet 2 lll Ii II yiuM TORNEYS.

Jan. 6, 1931. H. J. KERR 1,788,162

' WATER TUBE BOILER Original Filed Dec. 28, 1923 6 Sheets-Sheet. 3

INVEN-TOR.

I a a. ATTORNEYS.

Jan. 6, 19310 H. J. KERR 1,788,162-

WATER TUBE BOILER Original Filed Dec. 28, 1923 6 Sheets-Sheet 4 ,vmw mmunr jam. 35, 193E, H, J. KERR I WATER TUBE BOILER Original FiledjDec. 28, 1923- Sheets-Shet 5 Patented Jan. 6, 1931 UNITED STATES PATENT OFFICE HOWARD a. KERR, or EL uoRA. new JnRsEY, AssIenoR To run RARcocK a wrLcox comm, or BAYONNE, NEW JERSEY, A CORPORATION or NEW JE SEY WATER-TUBE RoIL R Application filed December 28, 1928 Serial No. 68$,i27. Renewed Hovember 17,1986.

My present invention relates to water tube boilers having horizontally inclined water tubes in' which provision is made for preventing-or minimizing the accumulation of slag on the tubes.

Fig. 5 is a section on thefline 5-5 of Fig. 3;

Fig. 6 is a view similar to Fig. 1 showing a modification; Fig. 7 is a section on the line.

7'-7 of Fig. '6; F i 8 is a view similar to Fig. -6, showing still another modification;- Fig. 9 is a section on the line 9-9 of Fig. 8;

Fig. 10 is apartial sectional elevation of a water tube jmiler, showing still another modification, Fig. 11 being a section on the line 11- -11 of Fig, 10; Fig. 12 is a partial sec- Q5 tional side elevation of a water tube boiler, showing another form, Fig. 13 being a section on the line 1313 of Fi 12; Fig. 14 is a sectional side elevation o the lower part of a water tube boiler showing a method of .installing my invention in boilers already built, gig. 12 being a sectionlon the line 15-'-15 of Eike reference characters indicate like parts in the severalviews.

.with certain grades of fue molten particles of slag-producing material are carried up from the surface and on contactlng with the boiler tubes, adhere thereto in a more or less difliculty by opening up the flow spaces through the lowermostv rows 'of tubes in a water tube boiler having horizontally inclined tubes, to reduce the velocity of the gases through such lowermost tubes below what it would be with the usual arrangement,

and my present invention relates to such As is well known, particularly when certain types of forced-blast stokers are used.

structures in which the tubes in the lowermost rows are arranged so as to give this reduced'velocity more effectively, and so'that the spaces betweenthe tubes will not readily become clogged by slag which may accumulate on the tubes. v I have found that I can arran e the tubes in the lowermost rows so that t e tubes in successive rows are either directly over each other or have a staggered relation, provided '30 the vertical distance between the'rows-or the horizontal spaces between the tubes in the same rows or both are properly arranged.

'I have found that when the tubes in the lowermost rows are staggeredbut with a tube in'an upper row only a relatively short distance above-or to one side of a'tube in the next lower row, the slag particles will collect on the bottom of such upper tube and gradually extend downwardly in a more or" less plastic condition .until it touches the tube in the lower row or even maybe forced over againstsuch tube by the draft. As soon as contact is made, the plastic slag chills to a degree and closes the passage between such upper and lower tubes. v y my invention I-arrange the tubes in two successive rows, as, for instance, the lowermost row'and the one above it, not only so that the deposit of slag will be reduced due to the reduction of the velocity of the gases, but also in such a way that any accumulation ofslag on the tubes of the lower most rows, as it extends downwards, will not form a continuous bridge across the flow spaces, since the accumulation will tend to drop from the tube before it reaches-to the next lower tube,'and in thus dropping off, it will either clear the lower tube entirely or else will temporarily bridge the space between a pair of tubes in the lower row from which it may be quickly melted therefrom by the contact of the flame.

Referring now to the arrangement of tubes shown in Figs. 1 and 2', the boiler shown is 5 of the well-known type having uptake head ers or water compartments '10 and 11 connected by nipples 12 and downtake headers orwater compartments 13 and 14 connected by nipples 15. Between the water compartin the main bank.

" I have found by cumulation of slag Twill tube before its lower end contacts with a tube, in thenext lower row.

and the compartment ].0, a transverse gas pass across, themain bank, a. second cross baffie 22 directing the gases back and forth across the tubes to the gas outlet.

In the form shown, a special water compartment 23 is located f be'low the uptake headers 11 and connected thereto by nipples 24. Spaced from the tube s'17 and from each other are three rows of tubes 25,26 and 27,

.the latter extending from the special water compartment- 23 to the downtake header 14. 'Below the tubes is' afurnacechamber 28- provided with a forced blast underfced stoker 29, the chamber 28 being arranged so that substantially the entire length of the 25 heat of the furnace.

lowermost tubes are exposed to the radiant As shown in Fig. 2, in the form illustrated in Fig. 1, the t'ubes in the group 17 as is also true of the group of tubes 16, are'arranged inthe usual manner, with the rows spaced relatively closely ina vertical direction and the tubes in successivezrows being staggered, as is also the usual arrangement, in order to obtain the best heat transfer.

As will be seen'by an inspection of Fig. 2,

' the tubes in-the rows 25, 26 and 27 are also staggered relatively to' each other'in successive rows, but the vertical distances between therow centers or between the tops of the "tubes in one row and the bottoms of the tubes in the next higher row are much greater than the corresponding distances'in the tube arrangement in the main bank. As illustrated, the distance between thecenter lines of the rows of slag screen tubes is equal to a mul-.

tiple of the distance between the planes of the center lines of two adjacent rows of tubes When slag particles are carried upward with the gases, such particles pass between the tubes in the row- 27, strike the tubes either .of the row 26 or therow-25 and collect thereon, as described above, this accumulation gradually extending downward in a plastic distance between condition. By making the the rows relatively great and preferably, as experience, providing a space between the tops and the bottoms of adjacent 'rows' equal to at least a tube diameter, s'ufiicient space is provided'sothat the ac.-

drop off of an upper when the tubes are staggered, as shown Y in F ig; 2, slag may drop, 'fo'r instance,-from one' of the tubes in row 26 and will fall into the space between a pair of tubes in the row 27. It may in some instances adhere to the tubes 27, but such adherence is usually only temporary, because this slag will then be subjected to the intense heat of the flame and will be heated to such a high temperature that it will melt and drop off into the furnace.

may be inserted to scrape the accumulated slag from the tubes. In connection with the boiler shown in Fig. 1, I have provided an illustrative arrangement to this end which is best shown in Figs. 3, 4 and 5.

In this arrangement, a series of metallic plates 30 are held to the nipples 24 by U- shaped members 31. Each of the plates 30 is provided with an opening 32 having a cover 33 of a known type, which can be raised and held in its raised position,-so that a cleaning tool may be inserted thro'ugh the opening 32 and between a pair ofnipples 24 to scrape the accumulated slag from the tubes 26 and 27. The space above the opening 32 may be filled with'any suitable plastic material 34.

In the arrangement shown in Fig. 6, the uptake water compartments 35 and the downtake water compartments 36are connected by a main bank of water tubes 37 which are staggered in the usual manner, as shown best in Fig. 7 these water compartments 35 and 36 being connected to a cross drum 38, 'in the usual manner, from which drum steam passes to a superheater 39 placed above the main bank.

Below the main bank of tubes 37 are three rows-of tubes 40, 41 and 42, the rows and 4l 'being spaced from the main bank 37 but having the usual staggered relation to each other, as shown best in Fig. 7 and the row 42 extending from a special water chamber 43 connected to the uptake headers by nipples 44, the row 42 being spaced aconsiderable distance below the row 41. A horizontal baflie 45 extends along the row 40 and joins a vertical cross baffle 46 extending acrossthe space between the main bankand the row 40. A short horizontal baflle 47extends along the lowermost rows of tubes in the main bank to join a vertical baflie 48 extending across themain bank. A second vertical bafile 49 directs the-gases to the gas outlet.

The furnace chamber' 50 extends beneaththe water tubes, the latter being exposed for the major portion oftheir length to the radiant heat from the furnace, the furnace having'in this instance a pair of forced-blast unde'rfeed stokers 51 oppositely disposed.

As will be 'seen in Fig.

7, the row 42 is-widelyspaced from the. next upper row 41 so that although the tubes inthese two rows are stag- 'gered relatively to each other, neverthless the slag accumulating on the tubes of row 41 cannot readily bridge across the two rows.

"f In the arrangement shown in Fig. 8, the uptake water chambers 52 and downtake water chambers 53 are connected by a main bank of tubes, 54, the'water chambers being, in turn, connected to the drum 55 in the usual man"- ner, and-a superheater 56 located above the main bank, receiving steam from the drum 55. The tubes in the main. bank have the usual staggered arrangement, as shown best in Fig. 9. l Below the main bank and spaced therefrom Y {are three rows of tubes 57 '58, and 59, the

tubes -59-extending from a special water chamber 60, connected to the uptake water chambers 52 by nipples 61 and at the opposite end extending into a mud drum 62, connected by nipples 63 to the downtake water chambers. The space between the rows 59 and 58 is relatively great, and in this form I have also increased-the space between the rows 58 and 57, particularly at the entrance to the first transverse pass across the main bank formed by the inclined bafile 64, by bending the cen-' ters of the tubes 58 downward, as shown best in Fig. 8. Above the tubes 57 is a horizontal baffle 65 extending to :the lower end of the.

.bafiie 64 anda transverse ba-file 66 directs the gases to the gas outlet. ,In this arangement, as shown best in Fig. 9, in order to open up the spaces between the lowermost rows of tubes still further, as may be desirable in some-instances, I have made the horizontal spaces between the walls of adjacent tubes of each-of the two lowermost rows very-much wider than usual, the tubes preferably being spaced at least double the horizontal distance between the tubes in the ma-in bank, and I also preferably arrangethe "tubes in the two lowermost rows in staggered ,i'el'ation so that as slag accumualtes on the tubes of the row 58 and falls, it will not strike .the tubes of the row 59 but will fall directly into the furnace chamber.

In-this arrangement, while I have shown the space between the rows 58 and 59 as rela- -t;i velylarge, itwill be understood that with a sufiicientlateral spacing between the walls of adjacenttubes in atleast the two lowermost rows, the vertical spacing of-these rows ,can be greatly reduced, and in fact, if desired, mayin some instances be no greater than the vertical spacing. in the tubes in the -main bank, provided that no tubein the lowermost row is sufficiently near to the path of accunulat-ed slag extending down or falling from .a-tube in thenext higher row to permit contact of such slag with a tube in the next .lower-row-to bridge over the fiow spaces. 1 In Figs. 10 ;and 11-1 have shown still an- Tother modification. which is particularly adapted for application to boilers built in the usual manner and in which slagging difliculties develop. The uptake water chambers 67 and the downtake water chambers 68 are connected by a main bank of staggered tubes 69 (only two rows of which'are illustrated) and the boiler has a. horizontal baffle 71 and a transverse baflle '7 2, also of the well-known type. I Below the main bank is a row of tubes 73 spaced in the usual manner and below the row 73 are whatis essentially two rows 74 and 75, so far as the space beneath the first transverse gas passage across the main bank of tubes 69 is concerned, these two rows being go formed, however, by lowering the right-hand end in Fig. 10 of each alternate tube, so that x at theleft-hand end of Fig. 10, the ends of the tubes in the rows'74 and 75 are in the same horizontal plane and enter each of the headers, as shown in Fig. 11, but the lowered I tubes of the row 75 enter a special 'water com- 'will be seen from this arrangement that in the portion of the boilerdirectly beneath the first pass, at which place I have foundthe collection of slag is most' likely to, occur, there is provided a pair of rows of tubes in which the tubes are staggered relatively to each other but in which the horizontal distance between adjacent tubes in each row-is very much wider than. the horizontal distances between tubes in the rows in the main bank 69. I

In the arrangementshown in Fig. 12, the uptake water compartment 78 anddowntake water compartment 79 are connected by a main bank of staggered tubes 80- and below the main bank are three rows of tubes 81, 82 and 83, the latter extending between a special water compartment 84 connected by nipples 85 to the uptake water compartments 78 and at the other end the rows 83 being connected to the usual mud drum 86, connected to the downtake water compartments 79. The row of tubes 83 is spaced a considerable distance below the row 82, the rows 81 and 82 havin the usual spaced and staggered relation 0 the main bank and the tubes in the row 83 being staggered in relation to thetubes in the row 82. v In Figs. 14 and 15, Ihave shown an arrangement which may be applied to boilers already built, in which the headers are continuous and in which originally there were two. rows of tubes spaced from the main bank but having the usual staggered relation and the usual spaced relation. In such case Ileave the lowermost row 87 extending between the; uptake headers 88 and the downtake headers 89 and remove the row which would normallv engage with the steps-9O in the respective headers and substitute therefor a row 91 with their ends :bent as'shown ,best in Fig. 14, so 4 I portions of the .headers .88 and 89, at the asv to enter at right-angles with "the plain may be made suflicient to prevent the closing/u of the gas passages. By placing one row a ove the other, however, it is obvious that the distance between the rows 87 and 91 need not beas great as would be necessary if the tubes were staggered.

- It will be understood that the embodiment of my invention may be widely varied and that the forms shown are merely illustrative.

It will also be understood thatthe separate water compartment beneath. the uptake headers, which I have shown in some of the figures, may be of any desired form and may have a. plurality of water tubes entering it intead-of only one, as shown; By providing the spaces formed between the nipples connecting such special compartment with the uptake headerswith openable covers, clean-' ing tools may be inserted'irrespective of the number of tubes below such nipples, so that the lower tubes of the first pass may be readily cleaned.

I claim:

1. A water tube boiler having a furnace providedwitha type of firing apparatus which causes slag particles to rise with the gases entering the water tubes, said boiler aving .a bank ofwater tubes arranged in rows extending across the bank with the ends of the water tubes comiected .to water compartments, and a plurality of rows of slag screen water tubes between the furnace and said bank, with the distance between the planes of the center lines of said rows of slag screen tubes, for at least a portion of the length of the tubes, equal to a multiple of the distance between the planes of the center lines of two adjacent rows of tubes in said ,bank. V

2. A water tube boiler having a furnace provided with a type of firing apparatus which causes slag particles to rise .with the gases entering the water tubes, said boiler having a bank of water tubes arranged in rows extending across the bank with the ends of the water tubes connected to water compartments, and a plurality of rows of slag screen water tlibsbetweenthe furnace and said bank, having diameters at least as.

great as the diai neters of the tubesin said bank and with the distance between the planes of the center lines of said rows of slag screen tubes, for at least a portion of the length of the tubes, equal to a multiple of the distance between the planeof the center between the furnace and said bank having diameters at least as great as the diameters of the tubes in said bank and with theftubes in the row nearest the furnace staggered in relation to the adjacent row and with the distance between the planes of thecenter lines of said rows, for at least a portion of the length of the tubes, equalv to at least two tube diameters.

4. A water tube boiler having a furnace I provided with a type of firing apparatus which causes slag particles to rise with the gases entering the water tubes, said boiler having a bank of water tubes with their ends connected to water compartments, and a plurality of rows of slag screen water tubes between the .furnace and said bank having diameters at least as great as the diameters of the tubes in said bank and with the tubes in the row nearest the furnace stagge'redin relation to the adjacent row and with the distance between the. planes of the center lines of said rows, for at least a portion of the length of the tubes, equal 0: at least two tube diameters, thecenter-to-center distance between the tubes in said rows, measured in said planes, being equal to at least two tube diameters.

5. A water tube boiler havinga furnace provided with a type of firing apparatus which causes slag particles to rise with the gases entering-the water tubes ,said boiler having a bank'of water tubes with their ends connected to water compartments, and a' plurality of rows of slag screen water tubes between the furnace and said bank having diameters at least as great. as the diameters I of the tubes in said bank and with the tubes in the row nearest the furnace staggered in relation to the adjacent row, the center-tocenter distance between the tubes in said rows, measured in the planes of the diam eters'of the tubes in each row, being equal to at least two tube diameters.

6. A water tube boiler having a furnace provided with a type of firing apparatus whichcau s'es slag particles to rise with the ga'ses'entering the water tubes, said boiler having a bank of water tubes with their ends connected towater compartments, and a plurality of rows of slag screen water tubes between the furnace and said banklhaving diameters at least as at as the diameters of the tubes in said ank and with the tubes in the row nearest the furnace staggerefi in relation to the adjacent row, the center-tocenter distance between the tubes in said rows, measured in the planes of the diameters of the tubes in each row, being equal to at least two tube diameters, and the tubes in the second row from the furnace being positioned relatively to the tubes in the first row from the furnace so that vertical planes tangent to the sides of the tubes in the second row will pass between tubes in the first row.

7 A water tube boiler having a furnace provided with a type of firing appai atus which causes slag particles to risewith the gases entering the, Water tubesysaid boiler having a bank of water tubes with their ends connected to water compartments, and a plutubes in one of said rows bent between the ends of said tubes in a direction away from the tubes in the other of said rows to provide a greater distance between said rows for a portion of the length of the tubes than between the ends of the tubes in the two rows.

8. A water tube boiler having a bank of horizontally inclined water tubes connecting water compartments at front and rear, over which the furnace gass pass, a plurality of rows of water tubes below said bank and spaced a substantial distance therefrom, the two lowermost rows having the tubes therein spaced apart horizontally at least double the distance that the tubes of said bank are spaced apart horizontally, and being arranged instaggered relation to each other so that slag which accumulates on the tubes ofthe second row will, on falling,pass into the furnace without striking the tubes of the lowermost row.

9. A water tube boiler having a bank of horizontally inclined water tubes connectin water compartments at opposite ends thereo over which the furnace gases pass, a lurality of rows of water tubes disposed be ow said bank and spaced a substantial distance therefrom, the two lowermost rows having the tubes therein disposed substantially at equal distances apart in each row, said distances being at least double the distance that the tubes of said bank are spaced apart horizon-.

tally, and the tubes in said two rows being arf water u e e gt nec dap we st ms distance than the 'DWS1Ofthebanha-su .Qt'rl heater disposed in a space beypndgthe-banwater tubes" and in positiontobe contacted water tubes, said water-tubes beingsufiitient-K in number to cal s?!: substantially, thoroughmingling and subseguent combustion of; the gases before they reach the superh ate 'nandI steaming water-tubes beyondthe-superheater and in position to be heated by the gases after they leave the superheater. 5 v a p IIOWABDKJ. KERR.-

rality of rows of slag screen water tubes between the furnace and said bank, with the ranged in staggered relation to each other so that slag'which accumulates on thetubes of the second row will,- on falling, pass into the furnace without striking the tubes of the lowermost row.

10. In combination, a furnace having firing apparatus of the type which causes slag particles to rise with the rising gases, a water tube boiler disposed above said furnace and having a bank of horizontally extending inclined water tubes connecting water compartments at the front and rear, a plurality of rows of water tubes below said bank and eX posed to radiant heat of said furnace for the major portion of their length, said lower rows I w h y th gases t r-ithey l av tha i z 0i Y0 

